ICELAND // If your inner explorer has ever dreamt of conquering the Arctic, you'll love Vatnajökull - a megapark of glacial ice and volcanic landscapes established to protect the world's largest ice cap outside the poles. Formed by the merging of two parks in 2008, the massive reserve covers 14% of Iceland. The northern portion of the park, Jökulsárgljüfur, protects a unique subglacial eruptive ridge and 30km (19-mile) gorge, as well as the grand waterfall Dettifoss. The southern part is anchored by Skaftafell, a wildly popular collection of peaks and glaciers. Though visitors flock here, so vast is the wilderness that there's always a trail to call your own. Head for the famous basalt waterfall, Svartifoss, in the shadow of brilliant blue-white Vatnajökull, with its lurching